Veterans are three times more likely than the general population to develop chronic obstructive pulmonary disease (COPD), the fourth leading cause of US death. Current therapies are principally palliative, and have limited ability to restore Veterans to a sustained better quality of life. The goal of this work is to improving Veteran rehabilitation from lung disease by developing a novel artificial lung (AL) device which is optimized for CO2 removal. Recently, we developed an AL design based on concentric gating which improves overall device efficiency compared to current clinical devices. In this work, we will optimize this design to develop a CO2 removal artificial lung (CORAL) which is suitable for incorporation into a wearable system. In Aim 1, a 3D computer model of the CORAL will be built using Solidworks and blood flow simulations will be performed using the Solidworks Flow Simulation add-in. A porous media model will be used to model flow resistance due to the fiber bundle. Blood flow simulations within devices having varied fiber lengths and fiber bundle porosities will be performed. The simulations will be used to guide design of an optimized device that meets all stated specifications for the CORAL device. Once the design is chosen, components will be 3D printed and used for prototype fabrication. In Aim 2, CORAL devices will be fabricated and bench tested to experimentally determine pressure drop and gas exchange performance. In Aim 3, CORAL devices which meet gas exchange and pressure specification will be tested using an acute sheep model of hypercapnia. The successful completion of these aims will lead to a Merit Review application that will focus on the long-term implementation of the developed CO2 removal device. These studies will include chronic sheep experimentation and incorporation into an automated, wearable system, and will provide the information necessary to plan human clinical trials.